Abstract: An over-voltage protection circuit is disclosed herein for protection against over-voltage of an energy storage device while charging. The circuit operates within the operational limits of a battery-operated device, such as a mobile or handheld device. The over-voltage protection circuit comprises an over-voltage protection device, and an over-voltage protection controller. The controller allows current to flow to the over-voltage protection device only when an energy storage device is experiencing over-voltage.

Abstract: An apparatus and method is disclosed which allow a limited energy source (such as a low voltage battery stack or a low current computer auxiliary device power connection) to charge a high performance capacitive device, which in turn powers a low duty-cycle, high power load circuit (such as a packet-switched radio data transmitter).

Abstract: A battery disconnect system is provided for a device having a battery and load. The battery disconnect system includes a switch that is operative to connect the battery to the load when the switch is in a closed state. The switch is also operative to disconnect the battery from the load when the switch is in an open state. The battery disconnect system also includes a switch controller that is coupled to the switch. The switch controller is operative to cause the switch to enter the closed state in response to receipt of a first signal from a first external source. The switch controller is also operative to cause the switch to enter the open state in response to receipt of a second signal from a second external source.

Abstract: An improved power supply system involves load-leveling the large transient currents drawn by a high power, low duty-cycle load application circuit by means of a high performance capacitive charge storage device, such as a super-capacitor or a network of super-capacitors. The improved power supply system allows the high power load application circuit to be driven by a limited energy power source, such as a battery or the power supplied to a PCMCIA slot by a host computer. When the input voltage source is a battery, the improved power supply system allows for a substantial increase in the battery's operational life. The inventive system is particularly useful for managing power supply requirements for miniaturized wireless transmission systems, such as two-way pagers or radio modems, which employ low duty-cycle packet-switched RF transmitters.